The substituted amidine compounds of the invention can be prepared by a modification of known methods. Typical methods which can be so modified include the reaction of a nitrile with a trialkyloxonium fluoroborate to prepare an N-alkyl nitrilium salt in a procedure similar to that of Meerwein et al., Ber. 89, 209 (1956), Borch, J. Org. Chem., 34, 627 (1969), and Weintraub et al., J. Org. Chem. 33, 1679 (1968). The nitrilium salt is then reacted with a primary alkylamine to obtain the amidine. A number of N-monosubstituted and unsubstituted amidines are known. Craver et al., J. Pharm. Exptl. Therap. 99, 353 (1950); Netherlands Application No. 6,508,754, C.A. 65, 2181c (1966); U.S. Pat. Nos. 3,344,138, 3,417,122 and 3,334,137. b-Naphthamidine is disclosed by Markwardt et al., Pharmazie 1969 24(7), 400-2.